Native DNA

Compound Buffer Solution Only Denatured DNA Native DNA... 

In contrast to single-stranded DNA, native DNA adsorbs poorly to polystyrene (Engvall, 1976). This problem can be overcome by treating the polystyrene with a 1% solution of aqueous protamine sulfate for 90 min (Klotz, 1982), followed by three washes with distilled water and drying. Other polycationic substances, such as MBSA (Section 5.2.3.3, Ferrua et al., 1983) or poly-L-lysine (type VII B Sigma), may also be used (Leipold et al., 1983). Poly-L-lysine is suspended in water at a concentration of 1 mg/ml (which may... 

Calorimetric data on the heat of interaction of DNA (native, calf-thymus) with PF and EB, respectively, in 0.015 M and in 0.1 M phosphate buffer (pH = 7) at 25° are reported in Figure 4. Despite the scatter in the points, partly due to difficulties en-... 

Tensammetry has been widely used for studying the behavior of polynucleotides at the DME [88]. The double-helical DNA (native) is adsorbed at the DME in the region —0.2 and —0.9 V vs. SCE. A pronounced desorption peak appears at —1.1 V (Fig. 38 curve 2). The denatured single-stranded DNA (curve 3) is more strongly adsorbed due to higher adsorbability of DNA bases. Two peaks are observed, the peak at —1.1 V is believed to correspond to an interfacial reorientation of adsorbed DNA segments, whereas the more negative peak (at... 

Hippel, P.H. von, Wang, K.-Y. Dynamic aspects of native DNA structure kinetics of the formaldehyde reaction with calf thymus DNA. J. Mol. Biol. 61 (1971) 587-613... 

We have so far described the structure of DNA as an extended double helix The crys tallographic evidence that gave rise to this picture was obtained on a sample of DNA removed from the cell that contained it Within a cell—its native state—DNA almost always adopts some shape other than an extended chain We can understand why by doing a little arithmetic Each helix of B DNA makes a complete turn every 3 4 X 10 m and there are about 10 base parrs per turn A typical human DNA contains 10 base parrs Therefore... 

The native form of chromatin in cells assumes a higher order stmcture called the 30-nm filament, which adopts a solenoidal stmcture where the 10-nm filament is arranged in a left-handed cod (Fig. 5). The negative supercoiling of the DNA is manifested by writhing the hehcal axis around the nucleosomes. Chromatin stmcture is an example of toroidal winding whereas eukaryotic chromosomes are linear, the chromatin stmctures, attached to a nuclear matrix, define separate closed-circular topological domains. 

The consequences of these changes were impressive. The parental 434 repressor had no affinity for the P22 operator in vivo, but the redesigned 434 repressor controiled only P22 operators and not 434 operator regions in vivo. Purified redesigned 434 repressor bound specifically to P22 operator DNA in vitro and showed the same hierarchy of affinities for the three regions ORl, 0R2, and OR3 as native P22 repressor. 

One of the most thoroughly investigated examples of polymeric biomolecules in regard to the stabilization of ordered structures by hydration are the DNAs. Only shortly after establishing the double-helix model by Watson and Crick 1953 it became clear, that the hydration shell of DNA plays an important role in stabilizing the native conformation. The data obtained by the authors working in this field up until 1977 are reviewed by Hopfinger155>. 

A DNA fingerprint can be used for many purposes other than solving violent crimes. In particular, it can serve to identify deceased individuals. In June of 1998 the "Vietnam Unknown" buried in the Tomb of the Unknown Soldier at Arlington National Cemetery was identified by DNA technology. He was shown to be First Lieutenant Michael Blassie, shot down over Vietnam in May of 1972. DNA samples taken from his mother matched those obtained from his body. A month later Blassie, a native of St. Louis, Missouri, was reburied in a national cemetery located in that city. 

Mossbauer spectroscopic titration of [Me2Sn(IV)] and [MesSnflV)] hydroxides with ligands mimicking nucleic acid phosphate sites and with native DNA was the aim of work by Barbieri et al. A series of aqueous solutions of each system, formed by the organotin(IV) hydroxides and the phosphate ligands used... 

Small-angle X-ray scattering (SAXS), circular dichroism (CD), and UV spectroscopy at different temperatures were used to investigate the nature of calf-thymus DNA in aqueous solution, in the presence of [Me Sn] " (n = 1-3) species. The results demonstrate that the [MeSn(IV)] moiety does not influence the structure and conformation of the DNA double helix, and does not degrade DNA, as indicated by agarose gel electrophoresis. Inter alia, the radii of gyration, Rg, of the cross section of native calf-thymus DNA, determined by SAXS in aqueous solution in the presence of [Me Sn] " (n = 1-3) species are constant and independent of the nature and concentration of the [Me Sn] species. 

Dornase alfa is produced by genetically engineered Chinese Hamster ovary cells containing DNA encoding for the native human protein deoxyribunuclease I. It is purified by tangential flow filtration and column chromatography. 

II. PROPERTIES OF DNA AND NATIVE NUCLEIC ACID-BASED NANOSTRUCTURES... 

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